Add more interface flags to pcap_findalldevs().

[libpcap] / pcap-linux.c

diff --git a/pcap-linux.c b/pcap-linux.c
index a33f9977a91f5c728b94ecbdb5ac0045999fbb1a..5deff8c1090b2a717bb57c1d277c44a0eafe0ac7 100644 (file)
--- a/pcap-linux.c
+++ b/pcap-linux.c
@@ -2601,6 +2601,157 @@ can_be_bound(const char *name _U_)
        return (1);
 }
 
+/*
+ * Get additional flags for a device, using SIOCGIFMEDIA.
+ */
+int
+get_if_flags(const char *name, bpf_u_int32 *flags, char *errbuf)
+{
+       int sock;
+       char *pathstr;
+       FILE *fh;
+       unsigned int arptype;
+       struct ifreq ifr;
+       struct ethtool_value info;
+
+       sock = socket(AF_INET, SOCK_DGRAM, 0);
+       if (sock == -1) {
+               pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, errno,
+                   "Can't create socket to get ethtool information for %s",
+                   name);
+               return -1;
+       }
+
+       /*
+        * OK, what type of network is this?
+        * In particular, is it wired or wireless?
+        */
+       if (is_wifi(sock, name)) {
+               /*
+                * Wi-Fi, hence wireless.
+                */
+               *flags |= PCAP_IF_WIRELESS;
+       } else {
+               /*
+                * OK, what does /sys/class/net/{if}/type contain?
+                * (We don't use that for Wi-Fi, as it'll report
+                * "Ethernet", i.e. ARPHRD_ETHER, for non-monitor-
+                * mode devices.)
+                */
+               if (asprintf(&pathstr, "/sys/class/net/%s/type", name) == -1) {
+                       pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
+                           "%s: Can't generate path name string for /sys/class/net device",
+                           device);
+                       close(sock);
+                       return -1;
+               }
+               fh = fopen(pathstr, "r");
+               if (fh != NULL) {
+                       if (scanf(fh, "%u", &arptype) == 1) {
+                               /*
+                                * OK, we got an ARPHRD_ type; what is it?
+                                */
+                               switch (arptype) {
+
+                               case ARPHRD_LOOPBACK;
+                                       /*
+                                        * These are types to which
+                                        * "connected" and "disconnected"
+                                        * don't apply, so don't bother
+                                        * asking about it.
+                                        *
+                                        * XXX - add other types?
+                                        */
+                                       close(sock);
+                                       return 0;
+
+                               case ARPHRD_IRDA:
+                               case ARPHRD_IEEE80211:
+                               case ARPHRD_IEEE80211_PRISM:
+                               case ARPHRD_IEEE80211_RADIOTAP:
+                               case ARPHRD_IEEE802154:
+                               case ARPHRD_IEEE802154_MONITOR:
+                               case ARPHRD_6LOWPAN:
+                                       /*
+                                        * Various wireless types.
+                                        */
+                                       *flags |= PCAP_IF_WIRELESS;
+                                       break;
+                               }
+                       }
+                       fclose(fh);
+               }
+       }
+       free(pathstr);
+
+#ifdef ETHTOOL_GLINK
+       memset(&ifr, 0, sizeof(ifr));
+       strlcpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
+       info.cmd = ETHTOOL_GLINK;
+       ifr.ifr_data = (caddr_t)&info;
+       if (ioctl(sock, SIOCETHTOOL, &ifr) == -1) {
+               int save_errno = errno;
+
+               switch (save_errno) {
+
+               case EOPNOTSUPP:
+               case EINVAL:
+                       /*
+                        * OK, this OS version or driver doesn't support
+                        * asking for this information.
+                        * XXX - distinguish between "this doesn't
+                        * support ethtool at all because it's not
+                        * that type of device" vs. "this doesn't
+                        * support ethtool even though it's that
+                        * type of device", and return "unknown".
+                        */
+                       *flags |= PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE;
+                       close(sock);
+                       return 0;
+
+               case ENODEV:
+                       /*
+                        * OK, no such device.
+                        * The user will find that out when they try to
+                        * activate the device; just say "OK" and
+                        * don't set anything.
+                        */
+                       close(sock);
+                       return 0;
+
+               default:
+                       /*
+                        * Other error.
+                        */
+                       pcap_fmt_errmsg_for_errno(ebuf, PCAP_ERRBUF_SIZE,
+                           save_errno,
+                           "%s: SIOCETHTOOL(ETHTOOL_GLINK) ioctl failed",
+                           device);
+                       close(sock);
+                       return -1;
+               }
+       }
+
+       /*
+        * Is it connected?
+        */
+       if (info.data) {
+               /*
+                * It's connected.
+                */
+               *flags |= PCAP_IF_CONNECTION_STATUS_CONNECTED;
+       } else {
+               /*
+                * It's disconnected.
+                */
+               *flags |= PCAP_IF_CONNECTION_STATUS_DISCONNECTED;
+       }
+#endif
+
+       close(sock);
+       return 0;
+}
+
 int
 pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)
 {
@@ -2633,8 +2784,12 @@ pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)
 
        /*
         * Add the "any" device.
+        * As it refers to all network devices, not to any particular
+        * network device, the notion of "connected" vs. "disconnected"
+        * doesn't apply.
         */
-       if (add_dev(devlistp, "any", PCAP_IF_UP|PCAP_IF_RUNNING,
+       if (add_dev(devlistp, "any",
+           PCAP_IF_UP|PCAP_IF_RUNNING|PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE,
            any_descr, errbuf) == NULL)
                return (-1);